Correlation Between Visual Acuity and Foveal Threshold by Automated Perimetry With Size V Stimulus.

Background: Visual acuity has been shown to correlate with foveal threshold as determined by automated perimetry. Although automated perimetry with size V stimulus is commonly used in neuro-ophthalmology practice, the relationship between the visual acuity and the foveal threshold with this larger stimulus is not well known.

Methods: Retrospective study of patients who had undergone neuro-ophthalmology evaluation and visual field testing with automated perimetry using size V stimulus. Healthy controls were also recruited. Using visual acuity and foveal threshold, Pearson correlation coefficients were calculated, and basic foveal threshold statistics were stratified by visual acuity. Prediction intervals for visual acuities by various foveal threshold were also calculated.

Results: A total of 106 unique eyes were included. The final Pearson correlation coefficient between visual acuities was -0.795 for the right eye and -0.578 for the left eye, with a pooled correlation coefficient of -0.751 ( P < 0.001). A foveal threshold of at least 34 dB was present in 94.4% of eyes with 20/20 visual acuity, and a foveal threshold of greater than 35 dB was not observed in eyes with visual acuity of 20/40 or worse.

Conclusions: Foveal threshold as determined by automated perimetry using size V stimulus has moderate-to-strong correlation with visual acuity in patients undergoing neuro-ophthalmology evaluation.